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 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
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 * modification, are permitted provided that the following conditions
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 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package com.sun.org.apache.xerces.internal.impl.dtd;

/**
 * ContentSpec really exists to aid the parser classes in implementing
 * access to the grammar.
 * <p>
 * This class is used by the DTD scanner and the validator classes,
 * allowing them to be used separately or together.  This "struct"
 * class is used to build content models for validation, where it
 * is more efficient to fetch all of the information for each of
 * these content model "fragments" than to fetch each field one at
 * a time.  Since configurations are allowed to have validators
 * without a DTD scanner (i.e. a schema validator) and a DTD scanner
 * without a validator (non-validating processor), this class can be
 * used by each without requiring the presence of the other.
 * <p>
 * When processing element declarations, the DTD scanner will build
 * up a representation of the content model using the node types that
 * are defined here.  Since a non-validating processor only needs to
 * remember the type of content model declared (i.e. ANY, EMPTY, MIXED,
 * or CHILDREN), it is free to discard the specific details of the
 * MIXED and CHILDREN content models described using this class.
 * <p>
 * In the typical case of a validating processor reading the grammar
 * of the document from a DTD, the information about the content model
 * declared will be preserved and later "compiled" into an efficient
 * form for use during element validation.  Each content spec node
 * that is saved is assigned a unique index that is used as a handle
 * for the "value" or "otherValue" fields of other content spec nodes.
 * A leaf node has a "value" that is either an index in the string
 * pool of the element type of that leaf, or a value of -1 to indicate
 * the special "#PCDATA" leaf type used in a mixed content model.
 * <p>
 * For a mixed content model, the content spec will be made up of
 * leaf and choice content spec nodes, with an optional "zero or more"
 * node.  For example, the mixed content declaration "(#PCDATA)" would
 * contain a single leaf node with a node value of -1.  A mixed content
 * declaration of "(#PCDATA|foo)*" would have a content spec consisting
 * of two leaf nodes, for the "#PCDATA" and "foo" choices, a choice node
 * with the "value" set to the index of the "#PCDATA" leaf node and the
 * "otherValue" set to the index of the "foo" leaf node, and a "zero or
 * more" node with the "value" set to the index of the choice node.  If
 * the content model has more choices, for example "(#PCDATA|a|b)*", then
 * there will be more corresponding choice and leaf nodes, the choice
 * nodes will be chained together through the "value" field with each
 * leaf node referenced by the "otherValue" field.
 * <p>
 * For element content models, there are sequence nodes and also "zero or
 * one" and "one or more" nodes.  The leaf nodes would always have a valid
 * string pool index, as the "#PCDATA" leaf is not used in the declarations
 * for element content models.
 *
 * @xerces.internal
 */
public class XMLContentSpec {

  //
  // Constants
  //

  /**
   * Name or #PCDATA. Leaf nodes that represent parsed character
   * data (#PCDATA) have values of -1.
   */
  public static final short CONTENTSPECNODE_LEAF = 0;

  /**
   * Represents a zero or one occurence count, '?'.
   */
  public static final short CONTENTSPECNODE_ZERO_OR_ONE = 1;

  /**
   * Represents a zero or more occurence count, '*'.
   */
  public static final short CONTENTSPECNODE_ZERO_OR_MORE = 2;

  /**
   * Represents a one or more occurence count, '+'.
   */
  public static final short CONTENTSPECNODE_ONE_OR_MORE = 3;

  /**
   * Represents choice, '|'.
   */
  public static final short CONTENTSPECNODE_CHOICE = 4;

  /**
   * Represents sequence, ','.
   */
  public static final short CONTENTSPECNODE_SEQ = 5;

  /**
   * Represents any namespace specified namespace. When the element
   * found in the document must belong to a specific namespace,
   * <code>otherValue</code> will contain the name of the namespace.
   * If <code>otherValue</code> is <code>-1</code> then the element
   * can be from any namespace.
   * <p>
   * Lists of valid namespaces are created from choice content spec
   * nodes that have any content spec nodes as children.
   */
  public static final short CONTENTSPECNODE_ANY = 6;

  /**
   * Represents any other namespace (XML Schema: ##other).
   * <p>
   * When the content spec node type is set to CONTENTSPECNODE_ANY_OTHER,
   * <code>value</code> will contain the namespace that <em>cannot</em>
   * occur.
   */
  public static final short CONTENTSPECNODE_ANY_OTHER = 7;

  /**
   * Represents any local element (XML Schema: ##local).
   */
  public static final short CONTENTSPECNODE_ANY_LOCAL = 8;

  /**
   * prcessContent is 'lax'
   **/
  public static final short CONTENTSPECNODE_ANY_LAX = 22;

  public static final short CONTENTSPECNODE_ANY_OTHER_LAX = 23;

  public static final short CONTENTSPECNODE_ANY_LOCAL_LAX = 24;

  /**
   * processContent is 'skip'
   **/

  public static final short CONTENTSPECNODE_ANY_SKIP = 38;

  public static final short CONTENTSPECNODE_ANY_OTHER_SKIP = 39;

  public static final short CONTENTSPECNODE_ANY_LOCAL_SKIP = 40;
  //
  // Data
  //

  /**
   * The content spec node type.
   *
   * @see #CONTENTSPECNODE_LEAF
   * @see #CONTENTSPECNODE_ZERO_OR_ONE
   * @see #CONTENTSPECNODE_ZERO_OR_MORE
   * @see #CONTENTSPECNODE_ONE_OR_MORE
   * @see #CONTENTSPECNODE_CHOICE
   * @see #CONTENTSPECNODE_SEQ
   */
  public short type;

  /**
   * The "left hand" value object of the content spec node.
   * leaf name.localpart, single child for unary ops, left child for binary ops.
   */
  public Object value;

  /**
   * The "right hand" value of the content spec node.
   * leaf name.uri, right child for binary ops
   */
  public Object otherValue;

  //
  // Constructors
  //

  /**
   * Default constructor.
   */
  public XMLContentSpec() {
    clear();
  }

  /**
   * Constructs a content spec with the specified values.
   */
  public XMLContentSpec(short type, Object value, Object otherValue) {
    setValues(type, value, otherValue);
  }

  /**
   * Constructs a content spec from the values in the specified content spec.
   */
  public XMLContentSpec(XMLContentSpec contentSpec) {
    setValues(contentSpec);
  }

  /**
   * Constructs a content spec from the values specified by the given
   * content spec provider and identifier.
   */
  public XMLContentSpec(XMLContentSpec.Provider provider,
      int contentSpecIndex) {
    setValues(provider, contentSpecIndex);
  }

  //
  // Public methods
  //

  /**
   * Clears the values.
   */
  public void clear() {
    type = -1;
    value = null;
    otherValue = null;
  }

  /**
   * Sets the values.
   */
  public void setValues(short type, Object value, Object otherValue) {
    this.type = type;
    this.value = value;
    this.otherValue = otherValue;
  }

  /**
   * Sets the values of the specified content spec.
   */
  public void setValues(XMLContentSpec contentSpec) {
    type = contentSpec.type;
    value = contentSpec.value;
    otherValue = contentSpec.otherValue;
  }

  /**
   * Sets the values from the values specified by the given content spec
   * provider and identifier. If the specified content spec cannot be
   * provided, the values of this content spec are cleared.
   */
  public void setValues(XMLContentSpec.Provider provider,
      int contentSpecIndex) {
    if (!provider.getContentSpec(contentSpecIndex, this)) {
      clear();
    }
  }

  //
  // Object methods
  //

  /**
   * Returns a hash code for this node.
   */
  public int hashCode() {
    return type << 16 |
        value.hashCode() << 8 |
        otherValue.hashCode();
  }

  /**
   * Returns true if the two objects are equal.
   */
  public boolean equals(Object object) {
    if (object != null && object instanceof XMLContentSpec) {
      XMLContentSpec contentSpec = (XMLContentSpec) object;
      return type == contentSpec.type &&
          value == contentSpec.value &&
          otherValue == contentSpec.otherValue;
    }
    return false;
  }

  //
  // Interfaces
  //

  /**
   * Provides a means for walking the structure built out of
   * content spec "nodes". The user of this provider interface is
   * responsible for knowing what the content spec node values
   * "mean". If those values refer to content spec identifiers,
   * then the user can call back into the provider to get the
   * next content spec node in the structure.
   *
   * @xerces.internal
   */
  public interface Provider {

    //
    // XMLContentSpec.Provider methods
    //

    /**
     * Fills in the provided content spec structure with content spec
     * information for a unique identifier.
     *
     * @param contentSpecIndex The content spec identifier. All content spec "nodes" have a unique
     * identifier.
     * @param contentSpec The content spec struct to fill in with the information.
     * @return Returns true if the contentSpecIndex was found.
     */
    public boolean getContentSpec(int contentSpecIndex, XMLContentSpec contentSpec);

  } // interface Provider

} // class XMLContentSpec
